High-Throughput Screening Enables Ultrathin and High Thermal Conductivity All-Carbon Graphene Foam Thermal Interface...

Rising power density and integration in electronic chips demands advanced thermal interface materials. However, the poor thermal stability (exceed 230°C) and low in-plane heat dissipation ability of vertically aligned graphene-polymer composites limit hotspot management. In this study, an ultrathin all-carbon graphene foam is fabricated using poly (methyl methacrylate) (PMMA) microspheres as a template by a high-throughput screening strategy based on finite element analysis. The incorporation of PMMA templates establishes in-plane/through-plane thermal conduction network and generates acidic environment that promotes the ring-opening of epoxy by the release of carboxyl during the pyrolysis of PMMA. In addition, CO generated during PMMA pyrolysis drives oxygen functional groups in GO to decompose into H₂O and CO₂, thereby preserving the carbon atoms. Benefited from these, the graphene foam exhibits high thermal diffusivities of 51.8 and 608.6 mm² s^-1 in the through-plane and in-plane direction, respectively. Under a pressure of 40 Psi, bond line thickness can be reduced to 29 µm and graphene foam shows an ultra-low contact thermal resistance of 0.104 Kcm² W^-1. Moreover, it reduces 16°C at ceramic heater compared with commercial thermal pad, and exhibits excellent thermal stability under high-temperature of 300°C. This study provides a pathway for the development of ultrathin, high-temperature-resistant thermal pads.